Raggio confirmed Fowler had been stabbed, but declined to elaborate regarding her injuries.

On Saturday, Fowler and her 12-year-old brother were home alone in separate rooms when the boy told police an intruder entered the home, ABC News' Sacramento affiliate KXTV reported.

The 12-year-old called his parents, who alerted sheriff's deputies. However, after the intruder fled, the boy found his 8-year-old sister with severe injuries, according to KXTV. She was pronounced dead at the hospital.

Multiple law enforcement agencies were searching the area for the suspect on Sunday. Authorities said the man, who is described as 6-feet-tall with a muscular build, should be considered armed and dangerous.

Authorities are also asking for any information on anyone who may have left town unexpectedly after the crime or has unexplained injuries, according to an alert on the Calaveras County Sheriff's Office website.

Anyone with information is asked to contact a tip line at 209-754-6030.